What is a likely consequence of low space flow in a VAV system?

What is a likely consequence of low space flow in a VAV system?

• A. It may cause overcooling.
• B. It may cause poor air distribution.
• C. It may cause excessive noise.
• D. It reduces energy consumption.

Answer: (B)

When a VAV system delivers too little airflow to a space, the air in the room doesn’t circulate effectively. The room air can stratify or form pockets where the conditioned air doesn’t mix well with the return air, leaving some areas under-ventilated and uneven in temperature. This poor air distribution means occupants in different parts of the space don’t experience consistent comfort or adequate ventilation, which is the primary consequence. Other issues like overcooling, excess noise, or reduced energy use are less likely to be the direct outcome of simply low space flow. High velocity or noisy operation tends to come from high flow or poorly designed diffusers, while energy use can be complex—low flow can save energy in some cases but often at the expense of comfort and air quality.

When a VAV system delivers too little airflow to a space, the air in the room doesn’t circulate effectively. The room air can stratify or form pockets where the conditioned air doesn’t mix well with the return air, leaving some areas under-ventilated and uneven in temperature. This poor air distribution means occupants in different parts of the space don’t experience consistent comfort or adequate ventilation, which is the primary consequence.

Other issues like overcooling, excess noise, or reduced energy use are less likely to be the direct outcome of simply low space flow. High velocity or noisy operation tends to come from high flow or poorly designed diffusers, while energy use can be complex—low flow can save energy in some cases but often at the expense of comfort and air quality.